A hybrid finite-element method (FEM)/method of moments (MoM) technique is employed for specific absorption rate (SAR) calculations in a human phantom in the near field of a typical group special mobile (GSM) base-station antenna. The MoM is used to model the metallic surfaces and wires of the base-station antenna, and the FEM is used to model the heterogeneous human phantom. The advantages of each of these frequency domain techniques are, thus, exploited, leading to a highly efficient and robust numerical method for addressing this type of bioelectromagnetic problem. The basic mathematical formulation of the hybrid technique is presented. This is followed by a discussion of important implementation details-in particular, the linear algebra routines for sparse, complex FEM matrices combined with dense MoM matrices. The implementation is validated by comparing results to MoM (surface equivalence principle implementation) and finite-difference time-domain (FDTD) solutions of human exposure problems. A comparison of the computational efficiency of the different techniques is presented. The FEM/MoM implementation is then used for whole-body and critical-organ SAR calculations in a phantom at different positions in the near field of a base-station antenna. This problem cannot, in general, be solved using the MoM or FDTD due to computational limitations. This paper shows that the specific hybrid FEM/MoM implementation is an efficient numerical tool for accurate assessment of human exposure in the near field of base-station antennas.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1109/TBME.2002.807639 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
How low can you go: Restrictive transfusion strategies in major surgery and physiological triggers.
Best Pract Res Clin Anaesthesiol
December 2023
Department of Anesthesia, St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada; Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada; Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Li Ka Shing Knowledge Institute of St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada; Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada. Electronic address:
Anemia and red blood cell transfusion are associated with adverse outcomes. Large randomized trials have demonstrated that restrictive transfusion strategies can safely reduce patient exposure to transfusion, forming a foundational pillar of patient blood management. The restrictive transfusion thresholds in these trials ranged from 7 to 8 g/dL for different populations and this variability is reflected in recent guideline recommendations for transfusion triggers.
View Article and Find Full Text PDFUterotonics update.
Best Pract Res Clin Anaesthesiol
September 2024
Center for Reproductive Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, MA, USA; Harvard Medical School, USA. Electronic address:
Uterotonics are the mainstay of management for postpartum haemorrhage and an understanding of their use is essential for the obstetric anaesthetist. First-line uterotonics comprise oxytocin and carbetocin, which act on the oxytocin receptor, and recent research has shown that lower doses of first-line uterotonics can be used to adequate effect. The oxytocin receptor is known to undergo desensitisation with exposure to the agonist over time and with increasing concentrations.
View Article and Find Full Text PDFPrevalence of child maltreatment in Albania.
East Mediterr Health J
December 2024
Faculty of Medicine, University of Medicine, Tirana, Albania.
Background: Child maltreatment is a global issue that significantly impacts children's lives. In 2018, 32% of 15-year-olds in Albania reported experiencing physical abuse.
Aim: To assess the prevalence and sociodemographic correlates of child abuse and neglect in Albania.
Refinement of a Published Gene-Physical Activity Interaction Impacting HDL-Cholesterol: Role of Sex and Lipoprotein Subfractions.
Genet Epidemiol
January 2025
Clinical and Translational Epidemiology Unit, Massachusetts General Hospital, Boston, Massachusetts, USA.
Large-scale gene-environment interaction (GxE) discovery efforts often involve analytical compromises for the sake of data harmonization and statistical power. Refinement of exposures, covariates, outcomes, and population subsets may be helpful to establish often-elusive replication and evaluate potential clinical utility. Here, we used additional datasets, an expanded set of statistical models, and interrogation of lipoprotein metabolism via nuclear magnetic resonance (NMR)-based lipoprotein subfractions to refine a previously discovered GxE modifying the relationship between physical activity (PA) and HDL-cholesterol (HDL-C).
View Article and Find Full Text PDFA Soft Robotic Sleeve for Physiotherapy: Improving Elbow Rehabilitation in Baseball Pitchers.
Physiother Res Int
January 2025
Department of Biomedical Engineering, University of Engineering and Technology (UET) Lahore, Narowal Campus, Narowal, Pakistan.
Background And Purpose: Throwing a baseball involves intense exposure of the arm to high speeds and powerful forces, which contributes to an increasing prevalence of arm injuries among athletes. Traditional rigid exoskeletons and rehabilitation equipment frequently lack portability, safety, ergonomic design, and affordability. Traditional rehabilitation approaches frequently require therapist monitoring, resulting in therapy delays.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!